1. Field of the Invention
The present invention concerns a magnetic resonance system.
2. Description of the Prior Art
Magnetic resonance systems typically has a patient receptacle in a data acquisition unit (scanner) interacting with the patient in the receptacle. The scanner has at least one basic field magnet system, a gradient system and an RF transmission coil. A static basic magnetic field is generated by the basic field magnet system in a patient tunnel that is stationary relative to the scanner housing. Gradient fields are generated in the patient tunnel by the gradient system. RF excitation fields are generated in the patient tunnel by the RF transmission coil. This results in nuclei of the patient in the patient tunnel being excited to magnetic resonance. The patient receptacle has a subframe and a patient bed supported by the subframe. The patient bed bears the patient and is mobile relative to the subframe so that the patient (when he or she lies on the patient bed) can be conveyed through the patient tunnel relative to the subframe. The unit composed of the scanner and patient receptacle is normally arranged in an RF-sealed shielded compartment.
In principle it is possible to also use the RF coil to receive magnetic resonance signals excited by the RF coil operated in a transmission mode. This manner of operation, however, provides only qualitatively low-grade magnetic resonance signals. Therefore the magnetic resonance signals are normally acquired by means of local coils that are attached to the patient or to the patient bed, near the patient.
It is possible to connect the local coils via cables with an evaluation device for the magnetic resonance signals, but this requires the use of multiple cables. Furthermore, each cable must have a plug connection in order to be able to separate the local coils from the evaluation device.
It is known to convert magnetic resonance signals from local coils in analog form to a different frequency and to transfer them via an air gap to the evaluation device. This type of transmission, however, is limited to analog signals for reasons of the available bandwidth. Furthermore, only the magnetic resonance signals of a single local coil can be transferred to the evaluation device by means of this type of signal transmission.
In the future it is planned to digitize the magnetic resonance signals of the local coils as early as possible and to transmit them on in digital form. In principle it is possible to conduct this data transmission via cables. However, due to the required bandwidth of the digitized magnetic resonance signals the fear exists that a use of plug connections will not function reliably in practice.